The surface structure of sulfated zirconia: Studies of XPS and thermal analysis

Hino, Makoto; Kurashige, Mitsuhiko; Matsuhashi, Hiromi; Arata, Kazushi

doi:10.1016/j.tca.2005.11.042

Cited by 114 publications

(77 citation statements)

References 45 publications

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“…Consequently, the catalyst activity significantly decreased after SO 2 poisoning. The S 2p XPS of the sulphated Mn-Ce/Al 2 O 3 catalyst ( Figure 7d) had two sub-peaks at 168.7 eV and 169.7 eV, assigned to the SO 3 2-and SO 4 2− species, respectively [39,40]. This result confirmed that sulfate species were formed over the sulphated Mn-Ce/Al 2 O 3 .…”

Section: Xpssupporting

confidence: 52%

Poisoning Effect of SO2 on Honeycomb Cordierite-Based Mn–Ce/Al2O3Catalysts for NO Reduction with NH3 at Low Temperature

et al. 2018

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Honeycomb cordierite-based Mn-Ce/Al 2 O 3 catalysts were prepared by the impregnation method and used for low-temperature selective catalytic reduction (SCR) of NO x with NH 3 , with and without SO 2 and/or H 2 O in a homemade fixed-bed tubular reactor. The catalyst reached nearly 80% NO x conversion at 100 • C in the absence of SO 2 . However, SO 2 reduces the catalytic activity (80% to 72%) of the honeycomb cordierite-based Mn-Ce/Al 2 O 3 catalysts under identical conditions. This finding demonstrated that the catalyst exhibited high activity at low temperature and excellent SO 2 resistance in the presence of 50 ppm SO 2 . The fresh and sulfated honeycomb cordierite-based Mn-Ce/Al 2 O 3 catalysts were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), N 2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetry and differential thermal analysis (TG-DTA), and Fourier transform infrared (FT-IR) spectroscopy. Characterization results indicated that the deactivation by SO 2 was primarily the result of the deposition of ammonium hydrogen sulfate and sulfated CeO 2 on the catalyst surface during the SCR process. The formed sulfates depressed the catalytic activity via the blocking of pores and the occupation of active sites. Additionally, the competitive adsorption between SO 2 and NH 3 always decreased the catalytic activity.

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Section: Xpssupporting

confidence: 52%

Poisoning Effect of SO2 on Honeycomb Cordierite-Based Mn–Ce/Al2O3Catalysts for NO Reduction with NH3 at Low Temperature

et al. 2018

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“…As our DRIFT spectra of pyridine titrated WS 2 show, the parent chalcogenide possesses both Brønsted and Lewis acid sites in an approximately equimolar ratio. The latter likely arise from single atom S anion vacancies resulting in undercoordinated W atoms, which are expected to behave as classic Lewis acid centres, however the reaction of such Lewis centres with water and protic reagents [24] can produce Brønsted acid centres during esterification, and the latter are likely the active catalytic sites in this work. …”

Section: Accepted Manuscriptmentioning

confidence: 98%

A new application for transition metal chalcogenides: WS2 catalysed esterification of carboxylic acids

Santos

Durndell

Isaacs

et al. 2017

Catalysis Communications

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The first application of WS 2 , a well-known graphene analogue, as a solid acid catalyst for carboxylic acid esterification is reported. WS 2 exhibits excellent specific activities and high conversion to methyl esters of (65-90 %) for C2-C16 carboxylic acid esterification with methanol under mild conditions, with Turnover Frequencies between 80-180 h -1 , and outstanding water tolerance even under equimolar water spiking. WS 2 also exhibits good stability towards methyl propanoate in the continuous esterification of propanoic acid, and is a promising candidate for biofuels production.

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“…Comparing the structural and textural properties of the sulphated zirconias by non-aqueous method in this study with the conventional method as reported by other researchers [1,11] sulphate groups and zirconia cations. In both samples, it is evident that there is a direct relationship between the number of Brönsted acid sites and the amount of sulphate retained on the catalysts: this is in good agreement with other published researches.…”

Section: Resultsmentioning

confidence: 62%

“…Clearly, the O1s spectra for both samples were consistent as shown in Figure 6, indicating the presence of S 6+ in SO4 2− . Oxide oxygen of the zirconia at binding energies of 530.5eV/531.0eV and 532.5eV assigned to sulphate oxygen on the surface of the catalyst [1,10] were observed. The peak at 530.5eV/531.0eV ishigher for sample II indicating higher Oxide oxygen.…”

Section: X-ray Photoelectron Spectroscopy (Xps)mentioning

confidence: 99%

“…Several routes to synthesize solid acid catalysts have been developed. [1] reported the synthesis of various super-acid materials over the past 20 years, as well as developing procedures to produce solid superacids of extreme acidity on several catalysts supports including metal oxides. Researchers investigated the use of alumina and a modified form of catalyst with boron oxide.…”

Section: Introductionmentioning

confidence: 99%

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Sulphated Zirconia Catalyst Prepared from Solid Sulphates by Non-aqueous Method

Eterigho

Farrow

Ejejigbe³

2017

IJEE

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A B S T R A C TNon-crystallinesulphated zirconia catalysts were synthesised by a non-aqueous and non-conventional method. The effect of varying the molar ratio of sulphating agent to zirconium source was also investigated. The samples were characterized by X-ray diffraction, Energy Dispersive X-ray (EDX), Infra-red Spectroscopy (IR),X-ray Photoelectron Spectroscopy (XPS). The surface acidity was measured by the Pyridine-DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) technique. The structural and textural properties of the sulphated zirconia were studied. The EDX and XPS profiles suggested that both sulphated zirconia catalysts have similar zirconia and sulphate structures; however, both catalysts were amorphous. Deconvolution of their XPS O 1s spectra showed that the samples contained both oxide oxygen of zirconium and sulphate oxygen, which sample I showed a higher amount of sulphate oxygen. Adsorption of pyridine into the samples indicated that the higher amounts of Brönsted acid sites are presented in sample I with lower amount of sulphate during preparation. This opens up the possibility of controlling the degree and type of active sites on a catalyst by the amount of sulphate used for preparation. Sulphated zirconia catalyst with higher activity properties was achieved via a non-aqueous, environmentalfriendly method. The zirconia catalyst has great contribution towards energy production which is used for preparation and transesterification of fatty acids for production of biodiesel.

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The surface structure of sulfated zirconia: Studies of XPS and thermal analysis

Cited by 114 publications

References 45 publications

Poisoning Effect of SO2 on Honeycomb Cordierite-Based Mn–Ce/Al2O3Catalysts for NO Reduction with NH3 at Low Temperature

Poisoning Effect of SO2 on Honeycomb Cordierite-Based Mn–Ce/Al2O3Catalysts for NO Reduction with NH3 at Low Temperature

A new application for transition metal chalcogenides: WS2 catalysed esterification of carboxylic acids

Sulphated Zirconia Catalyst Prepared from Solid Sulphates by Non-aqueous Method

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